package core.util;

import  java.lang.reflect. * ; 

/************************************************* 
md5 类实现了RSA Data Security, Inc.在提交给IETF 
的RFC1321中的MD5 message-digest 算法。 
*************************************************/  

/**
* <p>Title: MD5加密</p> 
* <p>Description: 是MD5加密文件,能过getMD5ofStr方法对字符进行加密</p> 
* <p>Copyright: Copyright (c) 2003</p> 
* <p>Company: </p> 
*  @author  <a href="a-fei@sohu.com">a-fei</a> 
*  @version  1.0 
*  @created 2003-03-26 
*/  


public   class  MD5  { 
	
/**下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的， 
*这里把它们实现成为static final是表示了只读，切能在同一个进程空间内的多个 
*Instance间共享 */  
	
	static   final   int  S11  =   7 ; 
	static   final   int  S12  =   12 ; 
	static   final   int  S13  =   17 ; 
	static   final   int  S14  =   22 ; 

	static   final   int  S21  =   5 ; 
	static   final   int  S22  =   9 ; 
	static   final   int  S23  =   14 ; 
	static   final   int  S24  =   20 ; 

	static   final   int  S31  =   4 ; 
	static   final   int  S32  =   11 ; 
	static   final   int  S33  =   16 ; 
	static   final   int  S34  =   23 ; 

	static   final   int  S41  =   6 ; 
	static   final   int  S42  =   10 ; 
	static   final   int  S43  =   15 ; 
	static   final   int  S44  =   21 ; 

	static   final   byte [] PADDING  =   {  - 128 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  
							0 , 0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,
							0 , 0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  
							0 , 0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,
							0 , 0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,
							0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0 ,  0  } ; 

	/** 下面的三个成员是MD5计算过程中用到的3个核心数据，
	* 在原始的C实现中 被定义到MD5_CTX结构中  */  
	private   long [] state  =   new   long [ 4 ];  //  state (ABCD) 
	private   long [] count  =   new   long [ 2 ];  //  number of bits, modulo 2^64 (lsb first) 
	private   byte [] buffer  =   new   byte [ 64 ];  //  input buffer 

	/** digestHexStr是MD5的唯一一个公共成员，是最新一次计算结果的 
　 	16进制ASCII表示. */  
	public  String digestHexStr; 

	/** digest,是最新一次计算结果的2进制内部表示，表示128bit的MD5值. */  
	private   byte [] digest  =   new   byte [ 16 ]; 

	/** getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串 
	返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的． */  
	public  String getMD5ofStr(String inbuf)  { 
		md5Init(); 
		md5Update(inbuf.getBytes(), inbuf.length()); 
		md5Final(); 
		digestHexStr  =   "" ; 
		for  ( int  i  =   0 ; i  <   16 ; i ++ )  { 
				digestHexStr  +=  byteHEX(digest[i]); 
		}  
		return  digestHexStr; 
	}  
	
	//这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数 
	public  MD5()  { 
		md5Init(); 
		return ; 
	}  

	/** md5Init是一个初始化函数，初始化核心变量，装入标准的幻数  */  
	private   void  md5Init()  { 
		count[ 0 ]  =   0L ; 
		count[ 1 ]  =   0L ; 

		// /* Load magic initialization constants. 
		state[ 0 ]  =   0x67452301L ; 
		state[ 1 ]  =   0xefcdab89L ; 
		state[ 2 ]  =   0x98badcfeL ; 
		state[ 3 ]  =   0x10325476L ; 

		return ; 
	}  

	/**  F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是 
	简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们 
　　实现成了private方法，名字保持了原来C中的。  */  

	private   long  F( long  x,  long  y,  long  z)  { 
		return  (x  &  y)  |  (( ~ x)  &  z); 
	}  
	
	private   long  G( long  x,  long  y,  long  z)  { 
		return  (x  &  z)  |  (y  &  ( ~ z)); 
	} 
	
	private   long  H( long  x,  long  y,  long  z)  { 
		return  x  ^  y  ^  z; 
	}  

	private   long  I( long  x,  long  y,  long  z)  { 
		return  y  ^  (x  |  ( ~ z)); 
	}  

	/**FF,GG,HH和II将调用F,G,H,I进行近一步变换 
	FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4. 
	Rotation is separate from addition to prevent recomputation. */  

	private   long  FF( long  a,  long  b,  long  c,  long  d,  long  x,  long  s, long  ac)  { 
		a  +=  F (b, c, d)  +  x  +  ac; 
		a  =  (( int ) a  <<  s)  |  (( int ) a  >>>  ( 32   -  s)); 
		a  +=  b; 
		return  a; 
	}  

	private   long  GG( long  a,  long  b,  long  c,  long  d,  long  x,  long  s, long  ac)  { 
		a  +=  G (b, c, d)  +  x  +  ac; 
		a  =  (( int ) a  <<  s)  |  (( int ) a  >>>  ( 32   -  s)); 
		a  +=  b; 
		return  a; 
	} 
	
	private   long  HH( long  a,  long  b,  long  c,  long  d,  long  x,  long  s, long  ac)  { 
		a  +=  H (b, c, d)  +  x  +  ac; 
		a  =  (( int ) a  <<  s)  |  (( int ) a  >>>  ( 32   -  s)); 
		a  +=  b; 
		return  a; 
	}  
	
	private   long  II( long  a,  long  b,  long  c,  long  d,  long  x,  long  s, long  ac)  { 
		a  +=  I (b, c, d)  +  x  +  ac; 
		a  =  (( int ) a  <<  s)  |  (( int ) a  >>>  ( 32   -  s)); 
		a  +=  b; 
		return  a; 
	} 

	/**
	 * md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
	 * 函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private的
	 */
	private void md5Update(byte[] inbuf, int inputLen) {

		int i, index, partLen;
		byte[] block = new byte[64];
		index = (int) (count[0] >>> 3) & 0x3F;
		// /* Update number of bits */
		if ((count[0] += (inputLen << 3)) < (inputLen << 3))
			count[1]++;
		count[1] += (inputLen >>> 29);

		partLen = 64 - index;

		// Transform as many times as possible.
		if (inputLen >= partLen) {
			md5Memcpy(buffer, inbuf, index, 0, partLen);
			md5Transform(buffer);

			for (i = partLen; i + 63 < inputLen; i += 64) {

				md5Memcpy(block, inbuf, 0, i, 64);
				md5Transform(block);
			}
			index = 0;

		} else

			i = 0;

		// /* Buffer remaining input */
		md5Memcpy(buffer, inbuf, index, i, inputLen - i);

	}

	/**//*
		 * md5Final整理和填写输出结果
		 */
	private void md5Final() {
		byte[] bits = new byte[8];
		int index, padLen;

		// /* Save number of bits */
		Encode(bits, count, 8);

		// /* Pad out to 56 mod 64.
		index = (int) (count[0] >>> 3) & 0x3f;
		padLen = (index < 56) ? (56 - index) : (120 - index);
		md5Update(PADDING, padLen);

		// /* Append length (before padding) */
		md5Update(bits, 8);

		// /* Store state in digest */
		Encode(digest, state, 16);

	}

		 /**
		 * md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的 　　　　　
		 * 字节拷贝到output的outpos位置开始
		 */

	private void md5Memcpy(byte[] output, byte[] input, int outpos, int inpos, int len) {
		int i;

		for (i = 0; i < len; i++)
			output[outpos + i] = input[inpos + i];
	}

		/*
		 * md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
		 */
	private void md5Transform(byte block[]) {
		long a = state[0], b = state[1], c = state[2], d = state[3];
		long[] x = new long[16];

		Decode(x, block, 64);

		/*Round 1 */
		a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /**//* 1 */
		d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /**//* 2 */
		c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /**//* 3 */
		b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /**//* 4 */
		a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /**//* 5 */
		d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /**//* 6 */
		c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /**//* 7 */
		b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /**//* 8 */
		a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /**//* 9 */
		d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /**//* 10 */
		c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /**//* 11 */
		b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /**//* 12 */
		a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /**//* 13 */
		d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /**//* 14 */
		c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /**//* 15 */
		b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /**//* 16 */

		/* Round 2 */
		a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /**//* 17 */
		d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /**//* 18 */
		c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /**//* 19 */
		b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /**//* 20 */
		a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /**//* 21 */
		d = GG(d, a, b, c, x[10], S22, 0x2441453L); /**//* 22 */
		c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /**//* 23 */
		b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /**//* 24 */
		a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /**//* 25 */
		d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /**//* 26 */
		c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /**//* 27 */
		b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /**//* 28 */
		a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /**//* 29 */
		d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /**//* 30 */
		c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /**//* 31 */
		b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /**//* 32 */

		/*Round 3 */
		a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /**//* 33 */
		d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /**//* 34 */
		c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /**//* 35 */
		b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /**//* 36 */
		a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /**//* 37 */
		d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /**//* 38 */
		c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /**//* 39 */
		b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /**//* 40 */
		a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /**//* 41 */
		d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /**//* 42 */
		c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /**//* 43 */
		b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /**//* 44 */
		a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /**//* 45 */
		d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /**//* 46 */
		c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /**//* 47 */
		b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /**//* 48 */

		/* Round 4 */
		a = II(a, b, c, d, x[0], S41, 0xf4292244L); /**//* 49 */
		d = II(d, a, b, c, x[7], S42, 0x432aff97L); /**//* 50 */
		c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /**//* 51 */
		b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /**//* 52 */
		a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /**//* 53 */
		d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /**//* 54 */
		c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /**//* 55 */
		b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /**//* 56 */
		a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /**//* 57 */
		d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /**//* 58 */
		c = II(c, d, a, b, x[6], S43, 0xa3014314L); /**//* 59 */
		b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /**//* 60 */
		a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /**//* 61 */
		d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /**//* 62 */
		c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /**//* 63 */
		b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /**//* 64 */

		state[0] += a;
		state[1] += b;
		state[2] += c;
		state[3] += d;

	}

		/**
		 * Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的， 只拆低32bit，以适应原始C实现的用途
		 */
	private void Encode(byte[] output, long[] input, int len) {
		int i, j;

		for (i = 0, j = 0; j < len; i++, j += 4) {
			output[j] = (byte) (input[i] & 0xffL);
			output[j + 1] = (byte) ((input[i] >>> 8) & 0xffL);
			output[j + 2] = (byte) ((input[i] >>> 16) & 0xffL);
			output[j + 3] = (byte) ((input[i] >>> 24) & 0xffL);
		}
	}

		/*
		 * Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
		 * 只合成低32bit，高32bit清零，以适应原始C实现的用途
		 */
	private void Decode(long[] output, byte[] input, int len) {
		int i, j;

		for (i = 0, j = 0; j < len; i++, j += 4)
			output[i] = b2iu(input[j]) | (b2iu(input[j + 1]) << 8)
					| (b2iu(input[j + 2]) << 16) | (b2iu(input[j + 3]) << 24);

		return;
	}

		/*
		 * b2iu是我写的一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
		 */
	public static long b2iu(byte b) {
		return b < 0 ? b & 0x7F + 128 : b;
	}

		/**
		 * byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
		  * 　因为java中的byte的toString无法实现这一点，我们又没有C语言中的 sprintf(outbuf,"%02X",ib)
		 */
	public   static  String byteHEX( byte  ib)  { 
		char[] Digit  =   { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' } ; 
		char  [] ob  =   new   char [ 2 ]; 
		ob[ 0 ]  =  Digit[(ib  >>>   4 )  &   0X0F ]; 
		ob[ 1 ]  =  Digit[ib  &   0X0F ]; 
		String s  =   new  String(ob); 
		return  s; 
	}
	
	public   static   void  main(String args[])  { 

		MD5 m = new MD5(); 
		
		if  (Array.getLength(args)  ==   0 )  {  // 如果没有参数，执行标准的Test Suite 

			System.out.println( " MD5 Test suite: " ); 
			System.out.println( " MD5(\" \" ): " + m.getMD5ofStr( "" )); 
			System.out.println( " MD5(\" a \" ): " + m.getMD5ofStr( "a" )); 
			System.out.println( " MD5(\" abc \" ): " + m.getMD5ofStr( "abc" )); 
			System.out.println( " MD5(\" message digest \" ): " + m.getMD5ofStr( "message digest" )); 
			System.out.println( " MD5(\" abcdefghijklmnopqrstuvwxyz \" ): " +  
					m.getMD5ofStr( "abcdefghijklmnopqrstuvwxyz" )); 
			System.out.println( " MD5(\" ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 \" ): " +  
					m.getMD5ofStr( "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" )); 
		}  
		else  
			System.out.println( "MD5( " + args[0] + " )= " + m.getMD5ofStr(args[0])); 
	}
	
	
}